The present invention relates to a method for the stabilization of lactose enriched aqueous mixtures and more particularly to the stabilization of concentrated whey such as cheese whey.
Cheese whey is obtained as a by-product in the manufacture of cheese and generally has a solids content of about 3 to about 8% by weight. The cheese whey, which is about 90% water, contains lactose, some protein and small amounts of vitamins and minerals. Cheese whey has long been used as an animal food supplement, the lactose serving as a high energy nutrient. However, because of its high water content and, accordingly, low nutrient content, transportation of the cheese whey for long distances for use as an animal food supplement is not economical.
Ideally, one would concentrate the cheese whey to a product containing about 35 to 55% by weight solids without removal of any lactose. Such a material would be economical to transport for use as an animal food supplement. However, there are problems associated with concentrating the cheese whey to provide a higher solids content. Highly concentrated cheese whey tends to "set up" due to lactose crystal growth. Such a product is essentially non-flowable. This non-flowable characteristic of concentrated whey makes its use as an animal food supplement uneconomical because special handling equipment must be employed to transport the material and incorporate it into the animal food.
In an effort to make greater utilization of cheese whey as an animal food supplement, several approaches have been used. One technique involves essentially complete removal of the water from the cheese whey leaving a powder which can be easily handled and transported. This process is time consuming, requires a great deal of energy to effect evaporation of the water and, if not properly carried out, may result in degradation of the dried whey. A second approach which has been used is to remove part of the lactose from the cheese whey and concentrate the remaining product until it has a 35 to 45% by weight solids content. The latter approach is undesirable since it dilutes the lactose content of the whey and thereby reduces its value as an animal food supplement.
An additional problem associated with cheese whey is that if the whey is not effectively utilized, as for example as an animal food supplement, it presents a disposal problem. Whey is a water pollutant and hence should not be discharged into streams, lakes or the like. Accordingly, a method which would make economical use of whey and thereby obviate its discharge as a waste product into streams as highly desirable from an ecological standpoint.